There was a ton of complicated logic here to work around
two problems:
- Same-type constraints were not represented properly in
RequirementReprs, requiring us to store them in strong form
and parse them out when printing type interfaces.
- The TypeBase::getAllGenericArgs() method did not do the
right thing for members of protocols and protocol extensions,
and so instead of simple calls to Type::subst(), we had
an elaborate 'ArchetypeTransformer' abstraction repeated
in two places.
Rewrite this code to use GenericSignatures and
GenericFunctionType instead of old-school GenericParamLists
and PolymorphicFunctionType.
This changes the code completion and AST printer output
slightly. A few of the changes are actually fixes for cases
where the old code didn't handle substitutions properly.
A few others are subjective, for example a generic parameter
list of the form <T : Proto> now prints as <T where T : Proto>.
We can add heuristics to make the output whatever we want
here; the important thing is that now we're using modern
abstractions.
Previously, the only way to get initializers was completing after the
name of the type:
Foo#^complete_here^#
Foo(#^or_here^#
And now it will also work in unadorned expressions:
#^a_top_level_completion^#
bar(a, #^walked_into_a_bar^#
Unfortunately, not all our clients handle this well yet, so it's
protected by a language option.
-code-complete-inits-in-postfix-expr
Swift SVN r27275
